EPA Issues New Rule for Particulates in the Air

"I can remember when the air was clean and sex was dirty." - George Burns

On June 14, 2012, the Environmental Protection Agency (EPA) announced proposed regulations revising National Ambient Air Quality Standards (NAAQS) under the Clean Air Act (CAA) for particulate matter (PM). EPA will be taking public comments on the proposed rule until August 31, 2012, and has set two public hearings in Philadelphia (July 17, 2012) and Sacramento (July 19, 2012) to discuss the proposed rule. EPA is issuing the rule in response to a court order from a lawsuit challenging earlier regulations published in 2006 during the Bush Administration, which were found not stringent enough under the CAA. The Court required EPA to put final rules in place by December 14, 2012.

EPA describes "particulate matter" as being "a complex mixture of extremely small particles and liquid droplets." "Particulate pollution" is "pollution is made up of a number of components, including acids (such as nitrates and sulfates), organic chemicals, metals, and soil or dust particles." It is measured as "fine" or "coarse" depending on the size of the diameter of the matter. "Fine" PM is 2.5 micrometers in size or smaller, while "coarse" PM is 2.5 to 10 micrometers.

The CAA mandates that EPA regulate air quality standards to protect public health ("primary standards") and for adverse environmental effects ("secondary standards"). EPA reviews these standards every five years and either issues new regulations or leaves existing regulations in place, depending on what the science indicates is protective of primary and/or secondary standards. For PM, the potential negative health affects relate especially to fine PM, which include "premature mortality, increased hospital admissions and emergency department visits, and development of chronic respiratory disease." The secondary or environmental standards relate to visibility, which in some cases can be quite extreme, like in China, for example. The complete science supporting EPA's decision, which includes 300 new epidemiological studies, can be found here (warning, it is over 2,000 pages long, with indices).

The proposed regulations lower the annual air quality standard from 15.0 micrograms per cubic meter air or µg/m3 to 12.0 to 13.0 µg/m3, but leaves the 24-hour standard the same as the previous standard (35 µg/m3 averaged over three years). As for secondary standards, PM would be regulated by complying with a visibility index ("deciviews"). The standards for "coarse" PM remain unchanged from the earlier version of the regulation.

If a geographic area fails to meet the standards, it is identified as a "nonattainment area" and local and state governments would then have to put into place controls that would allow the geographic area to reach "attainment" (i.e., meeting the numerical requirements) by 2020. As NAAQS standards (whether for PM or any other regulated pollutant) become tougher, more geographic areas that were once "attainment" under earlier standards become "nonattainment," which in turn results in additional regulation at the local and state level. States must then submit plans, called "State Implementation Plans" or "SIP" for EPA to review and approve, which demonstrates that the State can meet attainment status by 2020.

As with all rules, EPA will accept public comments, either directly or at the public hearings. It will respond to substantive comments received before August 31, 2012, and issue a final rule by December 14, 2012. EPA hopes that the new rules will pass judicial muster and result in billions in avoided health costs, while the cost of implementation is estimated at $2.9 million a year for meeting the 13.0 µg/m3 standard (upper range) and $69 million for meeting the 12.0 µg/m3 standard (lower range). As for what ways regulators can control PM emissions, EPA has published a draft of a list of potential control mechanisms.

UPDATE: The Washington Post published an article in which it suggests that the White House actually weakened this rule and bucked EPA's scientists who were urging a tougher rule.